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SEER Inquiry System - Report
Produced: 11/21/2025 2:51 AM
Question 20130054
Inquiry Details
References:
2007 MP/H Rules
Question:
Discussion:
Left upper lung lobectomy: Adenocarcinoma, poorly-differentiated (grade 3), tumor size 1.2 cm, confined to lung. Second primary lung tumor: adenocarcinoma, well-differentiated (grade 1), tumor size 0.9 cm, confined to lung. Diagnosis COMMENT: The two tumors, although both adenocarcinoma, show markedly different histologies and thus are classified as synchronous primaries. Multiple synchronous primaries are staged separately according to the 7th edition of AJCC.
The AJCC Staging Manual 7th ed states, "Multiple tumors may be considered to be synchronous primaries if they are of different histological cell types. When multiple tumors are of the same cell type, they should only be considered to be synchronous primary tumors if, in the opinion of the pathologist, based on features such as ..., they represent different subtypes of the same histologic cell type..."
In this case, the pathologist insists these are two synchronous primaries, although different subtypes are not given, because the tumors have different grades and look completely different under the microscope. The MP/H rules indicate this is a single primary. How many primaries are accessioned?
Answer:
For cases diagnosed 2007 or later, accession a single primary, adenocarcinoma [8140/3] of the left upper lobe lung [C341]. The steps used to arrive at this decision are:
Open the Multiple Primary and Histology Coding Rules Manual. Choose one of the three formats (i.e., flowchart, matrix or text). Go to the Lung MP rules because site specific rules exist for this primary.
Start at the MULTIPLE TUMORS module, rule M3. The rules are intended to be reviewed in consecutive order within a module. The patient has two tumors in the same lung with the same histology.
Do not use the AJCC Manual to make multiple primary decisions. Use the MP/H Rules to determine the number of primaries to accession.
